Gyroscopic inclinometer for aeroplanes



E. A. SPERRY GYROSCOPIC INCLINOMETER FOR A Dec. 1 1925- EROPLANES 2Sheets-Sheet 1 Filed Jan. 15 91 v A770 IVE! Dec. 1, 1925. 1,563,934

E. A. SPERRY GYROSCOPIC INCLINOMETER FOR AEROPLANEIS Filed Jan. 15 I 91v 2 Sheets-Sheet 2 7 0 v T 9 5 19!] l 68 E/MR/QSPERRY.

ATTORNEY 4 being removed.

Patented Dec. 1, 1925.

UNITED STATES PATE NT oFF1cE'.-7

ELMER A. SPERRY, F BROOKLYN, NEW YORK, ASSIGNOR To THE SPERRY GYROSCOPECOMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

GYRosOor-Ic IINCLINOMETERF FOR AEROPLANES;

To all whom, it may concern." I 3 Be it knownthat I, ELMER A.-SPERRY, acitizenrof the United States of America, residing at 1 505 Alber'marleRoad, Brooklyn, in the county of Kings and State of. New

York, have invented certain new and useful Improvements in GyroscopicInclinom'eters for Aeroplanes, of which the following is aspecification.

This invention relates to gyroscopic appliances for use on aeroplanes.One of the objects of the invention is to provide a simple and compactgyroscopic device of light weight and'operated without employinganymotor or other machinerequiring a source of power on the aeroplane.

. Further objects of the invention are .to improve upon the constructionof gyroscopic I apparatus of this character, by providing means forsuppressing 'or overcoming the effect 'of acceleratio'n pressuresthereon, and by improving upona fluid pressure form of driving means bywhich no disturbingtorques on the gyroscope are produced.

Referring to'the drawingsin which, what I now'consider to be thepreferred form of my invention is shown c i 'Fig' 1 is a plan 'view ofthe device constructed in accordance with my invention, th cover of oneof the gyroscopes being removed. r 1

Fig 2 is .a cross section of one of the gyro; scopic units takenon line22 "of Fig. 1.

-Fig. 3 is crossgsection on approximately line 3-3 of 2. v k

' Fig. 4 is an elevation of the rotor of the gyroscope which may bereferred-to as a top,

since its characteristicsresemble in several respects the ordinary top.

Fig. 5 is a front elevation of the supporting postand sleeve for the topwith its assoeiated-partsthereto attached. a

Fig. 6 is a correspondingyiew" of the sleeve only, the

Fig.7 Fig. 2'.

;'Fig. 8 is a diagrammatic View; on a smaller scale, of myinvention-showing the means used to continuously withdraw air from theinterior of the casing. F'g. 9 is a plan view showing the'gradua- .tionsoncover 8.

is a section on broken line 77 of .in structure at least, is theordinary top pendulum and other parts Application filed "January 15,1918. Serial in). 211,989:

10 is a detail. Fig. 11 is an enlarged longitudinal section on the innerportion of the Venturi tube. Fig. 1 is a plan View of'a rotor providedwith a'modified form of buckets or vanes,

Fig. 1 is "avertical section-of the same.

Fig. 2 is an enlarged vertical section of P- thesupporting post for thetog. i

v Perhaps the simplest form of gyroscope,

which, as is known, comprises arotor that rotatesor spins about and issupported on a 55 slightly rounded point; said point acting also as anaxis for supporting the top for oscillation about both horizontal axes.

.WVhile in the ordinary top the-center ofi gravity is locatedabove thepoint of sup- Q port, accordingto my invention, the center of gravity,is not necessarily so situated. Preferably it is located very close toand .slightly below-the pointiof support so that the top standssubstantially inneutral or indifferent equilibrium'when at rest where--L by along period of oscillation is secured. The center of gravity maybeshifted slightly without materially affectlng the operation of thegyroscope, since the physical effect, 30 which, causes it to straightenitself up, when spinning, lies in' the friction 'between the 'pointofsupport and the supporting surface.

This causes a torque, about substantially ver tical axes, causingprecession of the top 35 about a horizontal axis to a vertical position.

The top is shown as comprising-a rotor or fly-wheel 1, :having a heavyring 2 and a cut-out under portion 3. In the'center of the top is apoint 4 which supportstjhe top for rotation about a normally verticalaxis and at the same time allows the top free-- dom movement about bothhorizontalaxes' intersecting atv said point.

"The top .is preferably provided with-la es .spindle- 5 which acts as apointer. or inch-- cator, and cooperates with radial graduationslfi andwith circular graduations 7 and 7 on the transparent cover 8 to indicateboth the angle. and direction of inclination of the :vehicle' on whichthe instrument is mounted. Said cover is secured within a cap 9 threadedinto the top of the casing proper 10. the joint being tightly packed. IIlluminating means such as lamps 70 and 71 maybe provided, if desired.Said casresting on washers 16 or'the likel Prefer,

' surrounds the rotor and supports the sameon a post ll-secured to' the,bottom of the casing. Said casing, together with a.

companion case 10' is shown as resiliently 5 supported from a ring orframe 12 by means of a plurality of\rods-13, 13" and 13 which areadjustably threaded to said ring and locked thereto-by loclt nuts 14,the casing being supported on said rods .by springs 15 ably a downwardlyacting spring 17 is placed above said ring and acts between the cap 18.and the ring so that jars .will not affect the apparatus. Preferablythree such sup- 1'5 porting rods are provided for the gyroscopic vide.means for continuouslywithdrawing 2' a valve or other opening 18'through which air fromthe interior of said casing, relying upon theentrance of air into the casing in a proper direction and location torevolve the rotor. For this purposeI have provided the air is exhaustedfrom the casing 111 any manner, preferably in 'the manner hereinafterdescribed. a

One or more-openmgs' shaped 1n the form of approximately tangentialnozzles 19, 20,

21 and 22, are provided in the casing in the plane of the rotor 1. Therotor is provided with buckets or vanes 23 located in the plane of saidnozzles and adapted-to receive the jets ofa-ir'issuing therefrom.

Preferably. said vanes are. formed by incisions in t e periphery of therotor.- I find it important not -to makesaid incisions of materiallygreater breadth in the direction'of the axis of the rotor than thebreadth of the jets and they are preferably substantially less thanone-fourth the width of 'the periphery ofthe rotor as shown in thedrawings. While certain advantages such as increased driving powerresult from cutting .the vanes entirely across the face of the rotor,such construction I find isof great disadvantage, in that when. the.rotor be comes tilted somewhat the jets striking against the bucketsorlvanes in their inclined positions cause an unbalanced couple on thegyroscope about one of the horizontal axes and hence precession thereofabout the other horizontal axis. Said couple may be caused in part bythe fact that the bottoms of the buckets are not parallel to the jets inthe; inclined position and that the walls of the buckets ofler.resistance to the jet in an inclined plane. This action, of course,throwsthe gyroscope or top on and interferes with its accuracy. Whensaid vanes are of limited extent' however such' trouble is eliminated orreduced to a minimum for all ordinary.

conditions 'of the gyroscope, since the pewill perform this .ripherythereof may be made .spherical and highly polished.

0 o o u 1 Stud post 11 1s shown as comprlsmg a central supporting stem20 having. an axial bore 21' in which is located 'a' spring 22'supporting a rod 23. Said rod is provided adjacent its top with atapered or concave recess 24 in which the point 4 attachedto. the top 1rests.

Preferably said recess. is

flat at the bottom portion at which point a the wall 81 is substantiallyperpendicular for a short distance. On, the exterior of said post aslidable sleeve. 25 is mounted. Said sleeve, normallystan'ds in thelower position as indicated inFigs; '2 and 5, bu-t may beraised to anelevated position. to lift ,the pointof support of the top off the rod24. This may be accomplished by meansof handle 26 secured to a rod 27journaled adjacentthe bottom of the casing 10 and provided at its.innerportion with an inwardly extending arm 28. Said arm' engagesbetween flanges 29-30 located nearthe lower portion of the sleeve 25.It-will be readily apparent that byrbtation of the handle 26 sleeve 25maybe raised to lift the rotor ofl" the'deli cate bearing or point ofsupport. The handle 26 may be made of resilient material so as tospringpast and catch OVEI a lug 3O hold the sleevein the raised position atwill.

the extent of inclination of the gyroscope with respect to thecasing.IVhile the rod 'unction by striking against the inner edge 32 of'.thetop 9, I prefer to provide anti-friction means for this purpose soasnotto retard the rotation of the top more than necessary. is shown asa series of balls 33 mounted for rotation adjacent the top of sleeve 25so that when the gyroscope tilts over a predetermined amount, the bottomofthe top will strike againstQthe balls and preventfurther in clinationas in Fig. 2.

\Vhile the structure so far described opcrates with a fair degree ofaccuracy, I preventing or equalizing the disturbing effects ofacceleration .forces.of the-top. Said This means indicated in the dottedlines '(Fig. 10) on the exterior of the casing to v '05 Preferably meansare provided to limit means isshown as comprlsmg a plurality of nozzles34 and 35 -to whlch air-1s introduced by means of a common pipe 36leading to the exterior of the casinglO. The entrance l tov said pipe isshown as covered by "fine wire auze 38 to n'eventthe entrance. of

dust. In nnediately over but spaced is located a baffle plate or disk 39having an inner slot: or slots 40 and 40 extending at greater or lessdistance from saidnozzles around a predetermined portion'of the disk. INormally the slots are positioned so thatthe jet issuing from eithernozzle will not strike the under surface of the top. Upon a slightrotation in one direction, however, one .jet

prises a pendulum 44 pivoted at45 on stem 20. The pendulum is providedwith annupstanding pin 46 which engages a hole or slot in the disk 39 sothat as the endulum is swung in one direction it wil revolve the dlskm'the. opposlte dlrectlon. Said pendulum 1s, of course, responslveto ac-,celeration forces exerted thereon so that .if

the axis of the pendulumus fore andaft of the aircraft and if theaircraft is turned in the direction indicated by the arrow A at thebottom of Fig. 5, the pendulum willbe movedin the direction indicated bythe arrow 13 in Fig. 5 and thereby rotate disk 39 .in atlockwisedirection, as viewed in Fig. 3. This, 1t Wlll be seen, Wlll uncover thenozzle 34, and cause an upward pressureot {air to be maintained againstthe under sur face 3 of top 1 thereby exerting a force which is opposedto the acceleration forceacting" on the gyroscope at the time, assumingthat the gyroscope 1s pendulous or in other words support-L While theaxis of the pendulum may be placed in. any position on the aircraft, Iprefer to place it in such position that the pendulum will ,be affectedby the most frequent and persistent accelerationforces occurring in saidvehicle. It is, of. course, obvious that a pendulum may-be providedabout each axisif desired,'but a position allowing transverseoscillation is preferred. j

As above stated, I prefer to employ a plu-' rality of such tops 1, and1' which are driven in; opposite directions as indicated by the arrowsin Fig. 1. The reason for preferring two oppositelys rotating tops is toinsure having at least'one ofthe tops'correct at all times. Forinstance, if the aeroplane on whichthe apparatus was n'iounted wasturning in the direction of. arrow C Fig. 1) top 1, which is shown asrotating 1n the oppo site direction, would have a tendency to flop over,as indicated, while to 1 would remain unaffected. Similarly, i theaeroplane were turning 1n the other direction,

' top 1 would straighten up, 1 while top 1;. would tend to turn over.The casings 10 and l0 enclosing the two tops may be formed as one-orcon'nected bv nine 50. Each casing may be provided with an outlet, valve18 and 18, each or either of which may be connected to the airexhausting device. Preferably a valve or other obstructing device '51 isemployed between the-two casings, so

that if desired one gyroscope only may be operated the full force of theexhausting "extends to such use.

device being exerted on said gyroscope.- It.

will be readily apparent that said valvemay .from the other.

For exhaustin the air from the. casings,

I prefer to emp oy a device somewhat similar to a Venturi tube. Saiddevice may comprise a tubular member witha restr cted passage 56therein, each end of the member tapering outwardly, Fig. 8. If theaircraft is flying in the direction indicated by the arrow a/ in saidfigui'e, the air will flow with great speed through the said tube andrestricted passage, therebyreducing the pressure to a marked extentadjacent said passage. ,At or adjacent said restricted passage islocated a second smalltube 57 which is connected to either or both ofthe valves 18 and 18' by means of a pipe 58 having a branch pipe 59.Pipe 58 is shown as tapped into tube 57 adjacent arestricted passage 60therein as indicated in Fig. 11,

.Whereby' a double rarifaction of air, 'so to speak, is produced. pInaccordance with the provisions of the patent statutes, I have herindescribed the principle of operation of my invention, to-

L I y getherwiththe apparatus, which I now con-, has its centerofgravity below itspolnt of,

elder to represent the best embodiment thereof, but I desire to have itunderstood that the apparatus shown is only illustrative and that theinvention can be carried out by \other means. Also, while it is designedto use the various "features and elements in the combination andrelations described, some of these may be altered and others omittedwithout interfering with the more general results outlined. and theinvention Thus the buckets on the rotor may be formedby providing therotor 111 with an annular flange (Figs. 1 and 1) 112 and cutting. orforming vanesthercin sirnilarto sawteeth. It should be noted thatthedamping action of jets 84 and 35 is rendered effective not only whenpendulum 44 becomes inclined, due to acceleration forces and the like,but also when-the casing 10, becomes inclined :with .respect to thependulum, or in other words when. the

aeroplane is on an uneven keel. This action is advantageous rather thanotherwise since whatever disturbing effect is in troduced bv Havingdescribed my invention, what I I claim and desire to secure by LettersPatent is:

\ '1. In gyroscopic apparatus, the combina-i tion with a top, means .forblowing air on sa1d top in such direction as to exert a couple thereon,a pendulous device, and 'means responsive to inclination of said devicefor rendering effective said blowing means.

4. The combination with a gyroscope mounted for oscillation-about anaxis, of apendulous device mounted adjacentthereto, means for applying atorque on, said gyroscope about-said axis, ..and means responsive toinclination of the device about an axis substa'ntiallyparallel to saidaxis of oscillation for bringing into action said torque applying means.j

5. The combination with a gyroscope mounted for oscillation about aplurality of axes, of a pendulous device pivoted about an axis'and meansresponsive to inclination of the device for causing a torque 011 thegyroscope about an axis substantially parallelto the axis-of thependulum.

6. The combination with a gyroscopic top mounted for oscillation aboutan axis, of a device responsive to acceleration forces mounted adjacentthereto, and means rendered eifective by said device for exerting atorque on the gyroscope in a counter disurfaceof the t rection tothetorque produced thereon by the acceleration force causing actuation ofsaid device.

7. The combination with a gyroscopic top, of a support therefor, andmeans for limiting the extent of inclination of the top with respect tothe support comprising an antifriction bearingmember carried by saidsupport and ada ted to engage the under on inclination thereof. 8. Thecombinatlon with a gyroscopic top,

pivotal point of support for said rotor locatedclose to its center ofgravity and a remeans for lifting said rotor and point ofl said member.

' 12. In combinatioma casing, a gyro rotor mounted therein, means forexerting an upsetting couple on said rotor, said means comprising anozzle adjacent the side of'said rotor and communicating withtheexterior of said casing, and means for withdrawing air from said'casingto cause an inflow of. air

of a-support therefor. and means for limit-' ving the extent ofinclination. of'the top with respect to the support comprising a memberadapted to engage the top when its inclina-' tion exceeds apredetermined amount,, and antifriction means between said member andtop.

9. The combination with a gyroscopic top,

of a support therefor; and means for limitingthe extent of inclinationof the top with respect to the support comprising a member carried bysaid support and adapted to enthrough said nozzle.

13. Incombination, a casing, a gyro rotor mounted therein, means forexerting an upsettingcouple on said rotor, said means comprising anozzle'adjacent the 'side of said rotor and communicating with theexterior of said casing, means 'for. withdrawing air from said casing tocause, an inflow of air through said nozzle, means covering said nozzle,and means responsive to tilti ngofsaid casing for uncovering saidnozzle.

14. In a gyroscopic apparatus, a supporting post, agyroscopic topadapted to rotate on said post and a plurallty of bearing balls mountedon said post and adapted to 'be engaged by the top when the latterprecesses.

I 15. In combination, a'casing,-a gyro rotor mounted therein, means forexerting. a couple on said rotor,.said'means comprising a plurality ofnozzles .'adjacent opposite sides of the rotor, means for causing flowof air through said nozzles, means normally covering said nozzles, andmeans responsive to tilting of the casing for uncovring cer- .tain ofsaidnozzles. z

16: In combination, a casing, a gyro rotor mounted therein, means forexerting a couple on said rotor. saidmeans 'comprislng a pair of nozzlesadjacent opposite-sides of said rotor, means for causing how of a1rthrough said nozzles, means nornially coveringsaid nozzles, and meansresponsive to tilting of the casing for uncovering one of said nozzles.

' 17. In combination, a casing, a resilient mounting for said casing,a-rotor-,and a resiliently mounted member upon which said rotor isadapted'to spin.

gage the under surface of the top on inclina tionthereof beyonda'predeterminedamount, and antifriction means between said member andtop. Y

.10. In gyroscopic' apparatus, a rotor, a

18. In a gyroscoplc'apparatus, a rotor, a resiliently mounted supportingmember, means-whereby said rotor is pivotally mounted on said member,and means for lifting said rotor off said member.

,- 19. In gyroscopic apparatus, a closed casing, means for withdrawingair therefrom, agyro-whe'el said casing, a nozzle for "driving the sameadjacent thereto and connected to the outer air, and a second nozzlesaid casing, a nozzle for driving the same for damping the gyroscopealso connected adjacentthereto and conneetedto the outer to theouterair. air, and a second nozzle for damping the 10 20. In gyroscopicapparatus for aeroplanes, gyroscope also connected to the outer air.

a closed casing, means operable by the pas- In testimony whereof Ihaveafiixed my sage of the aeroplane through the air for signature.withdrawing air therefrom, a gyro-Wheel in 1 I ELMER A 'SPERRY.

